Print wheel indexing means



Nov. 12, 1963 H. J. DOLMAN PRINT WHEEL INDEXING MEANS 2 Sheets-Sheet l Onginal Filed June 24, 1957 Inventor HENRY JAMES DOL MM Nov. 12, 1963 H. J. DOLMAN PRINT WHEEL INDEXING MEANS 2 Sheets-Sheet 2 orlginal Filed June 24, 1957 ktikk L EFFFE Inventor HENRY] JAMES 120mm United States Patent 3,110,249 PRINT WHEEL INDEXHIG MEANS Henry .lames Dolmen, Pennywell Road, Bristol, England Griginal applies. =on dune 24, 1957, Ser- No. 667,653, now Patent No. 2,936,298, dated May 30, 1961. Divided and this application July 16, 1959, Ser. No. 827,506 Claims priority, application Great Britain June 25, 1955 5 Claims. (ill. rm- 79) The present invention relates to printing mechanism adapted to print letters or numbers on to various articles or surfaces. The printing mechanism according to the invention may be used for a variety of purposes where serial numbers are to be printed on successive articles or successive groups of articles, for example for printing tabs or labels to be attached to articles to be subjected to laundry or dry cleaning operations, under the action of heat and pressure by the means referred to in co-pending application Serial No. 667,653, on which issued Patent No. 2,986,298, dated May 30, 1961, of which this application is a division.

For such printing mechanism it is often desirable to provide an automatic change device so that after printing one numeral once or several times in succession, the number is advanced by one unit automatically or by the action of a shift means; in general this involves some form of ratchet feed as well as digit transfer mechanism. Heretofore it has been necessary to provide a feed ratchet between adjacent number Wheels to permit the wheels to be advanced serially. Since the number wheels should be generally placed as close as possible this means both that the feed ratchet must be thin and further the feed pawls acting on the teeth must be of thin material and it is difficnlt to reconcile the requirements for close spacing of the numerals or like characters and long working life. The primary object of the invention is to permit the number wheels to be placed very close one to the other while providing a reliable and satisfactory mechanical construction.

Such a printing mechanism includes printing wheels having printing characters on the peripheral face and feed teeth interspersed between the printing characters, step-by-step or serial rotation of the wheels being obtained by a feed pawl the working face of which is clear of the peripheral faces of the wheels except when engaging one of the feed teeth to rotate the wheel by one tooth space.

The feed pawl is preferably connected to a manual shift lever or hke member which is pivoted to a carrier rotatable concentrically with the number wheels and the feed pawl is subjected to the action of a spring which tends to hold the pawl clear of the periphery of the wheels; thus on actuation of the shift lever the feed pawl is first pivoted into engagement with one of the feed teeth in one or more of the wheels and on continued movement of the shift lever the wheels are moved forward by one step. On release of the shift lever the feed pawl moves away from the wheels and thus completes its idle back stroke without drag g over the printing faces of the wheels.

Preferably the wheels, and in some cases other printing wheels not provided with feed teeth for automatic rotation, are associated with index and setting wheels whereby the positions of all the wheels maybe set manually as desired.

One convenient construction suitable, for example, for laundry marking purposes, includes three number wheels with digit transfer mechanism so that serial numbers up to 999 may be printed, and two or more further wheels adapted to print other numerals or letters in line with the numbers, but these further Wheels (hereinafter termed letter wheels) are not associated with the transfer mechanism and are intended to be set by hand as required.

Any suitable form of digit transfer mechanism may be provided operative for some or all of the number wheels; for example the units wheel could be provided with one feed tooth deeper than the rest, while the tens wheel could also be provided with a deep feed tooth, but not so deep as that of the units wheel, and the feed pawl comprises stepped surface portions adapted to co-operate with said number wheels; then at the position in which tens transfer from the units wheel is required, the feed pawl drops into the deeper tooth so that the tens wheel is engaged by the pawl to move it forward one step while the units wheel is changing from 9 to 0. Likewise when hundreds transfer is required the deeper teeth both in the units wheel and in the tens wheel are engaged so that the feed pawl may move to a sufiicient extent that all three wheels are moved forward by one step and so on for any further wheels which may include transfer mechanism.

The features of the present invention will be further described with reference to the drawings; wherein:

FIG. 1 is a general view of a printing mechanism in accordance with the present invention,

FIG. 2 is a side view of FIG. 1, with the printing mechanism shown in vertical section looking along the line 2--2 of FIG. 1; and

FIG. 3 is a partial diagrammatic section view showing the arrangement of the index Wheels and their connection to the printing wheels.

The accompanying drawings show the mechanism in a form suitable for fitting to the table of the machine described in said Patent No. 2,986,298 so as to position the print wheels 1 in the printing position as shown in FIG. 6 of said patent immediately above the printing elements 111 shown therein so that the label or other article to be printed is pressed upwardly against the printing wheels 11% forming part of the unit. It is however to be understood that the component parts described may be utilised in conjunction with other serial printing mechanism, according to the intended purpose.

The printing unit shown comprises an outer casing 151 fixed in position and it may be provided with a detachable cover indicated at 151. The base of the casing whichtforms a vertical wall thereof when the unit is installed on the machine shown in the aforesaid specification, is provided with a flanged boss 152 surrounding a plurality of sleeves 153, 154, 155, 156, as well as a central spindle 157 which form coupling elements between the printing wheels and a plurality of index or setting wheels 153 which serve for manual setting of the printing wheels 1210 when required.

Each of the index wheels 158 is provided with a plurality of depressions 159 in a rim-like portion 160 of its periphery, said depressions being engaged by a spring ball element 161 to assist in locating the number wheels 110 in their various selected positions. The peripheral portion of each index wheel 158 is provided with markings corresponding to the printing elements on the wheels 119, so that the number to be printed will be immediately visible to an operator since the index wheels are located externally of the casing 150.

Each of the number wheels 110' is provided with a plurality of raised printing or marking elements adapted to print letters or numerals as required and in one convenient construction, two of the wheels, those mounted for example on sleeves 153, 154, are adapted to print letter characters while the other printing wheels associated with the sleeves 155, 156 and with the spindle 157 are adapted to print numerical references so that the complete character which is printed by the mechanism comprises two letters and three numerals.

At least some of the printing wheels 111 are arranged to be operated automatically step-by-step by the operation of a manual shift lever 162; as shown three of the wheels 3 11%} are number wheels and embody transfer mechanism so that serial numbers up to 999 can be printed in succession, change in the numbers being efiected by depression of the shift lever 162. v

The three number wheels 116 are provided with feed teeth 163 spaced around the periphery thereof and interspersed by the printing characters and to provide for the digit transfer mechanism one of the teeth of each of the units and tens wheels is provided with one deeper tooth as indicated at 164, the tooth 164 being deeper in the units wheel than in the tens wheel.

To effect actuation of the three number wheels for serial operation by the shift lever 162, the latter is pivotally mounted by means of a pivoted spindle 165 on a rotatable plate 166 movable coaxially with the printing wheels 111 In a convenient construction shown in FIG. 3 the plate 166 is mounted on a bush 167 held in the bore of the boss of the back plate of the casing 156-, being located between an endface of the boss and a flange 158 on the bush. The shift lever 162 is associated with a feed pawl 169 either attached thereto or formed integrally therewith as a unitary pressing. The plate 166 is provided with a projecting lug 170- attached to a return spring 171 whereby the plate 166 is moved against a stop 172 except on depression of the shift lever 162. A blade spring 174 acts upon the shift lever 162 in such a manner that it is retained in a normally inoperative position against a stop pin with the pawl 169 standing clear of the printing wheels 1111. The pawl 16? is provided with a wheel-engaging portion 175 having steps lying at different levels each step being adapted to engage one of the number group of the printing wheels 1113, the different steps in conjunction with'the relatively deeper teeth 164 in the units and tens wheel permitting digit transfer to be effected in well-known manner and as will be briefly explained hereinafter.

When automatic advance of the numerals to be printed is required the shift lever 162 is depressed. Initially the lever 162 pivots about the spindle 165' and the face 175 of the pawl 169 is engaged at least with the 'units Wheel 1143. After such engagement continued depression of the shift lever 162 causes rotation of the plate 166 coaxially with the number wheels and consequently at least the .units wheel is moved forward by the amount of one step forward. If at this particular forward step digit transfer had been required the face 175 would have entered the deeper tooth 164 of the unit Wheel 1111 and consequently the second step of the face 175 would have entered into engagement with one of the teeth of the tens wheel 11% so that these two wheels would then rotate together stepping the tens wheel forward by one step, while the unit wheel is passing from 9 to 0. Likewise if hundreds transer had been required also the deeper teeth 164 both of the unit wheel and of the tens wheel would have come into alignment and the face 175 would have moved inwardly to a suificient extent to advance the hundreds wheel by one step while the units and tens wheel together were moving from 99 to 6'0. 7

Various means may be adopted to permit printing from the printing wheels 11% on to the surface to be printed. For example in some cases the raised printing faces may be directly inked. Conveniently however, a marking ribbon is employed through which the impression is effected in a manner similar to a typewriter ribbon, but in this case conveniently a comparatively wide ribbon is preferably employed, the line of printing being disposed transversely of the ribbon as will be readily ap-.

parent from FIG. 1 where the ribbon is indicated at 178, being guided closely adjacent theprinting faces of the wheels so that the article to be printed is pressed upwardly towards the printing wheels, printing then being effected through the ink or other marking medium carried by the ribbon 178. The ribbon is conveniently supported on spools 17h mounted on spindles 1811 supported from the back plate of the casing 156. With this arrangement it is necessary to provide a gradual shift of the ribbon from one spool to the other in order that a fresh printing surface is brought into operation at each printing operation. Any convenient means may be provided according to the nature of the apparatus to obtain this progressive shift of the ribbon. As shown in FIG. 1 a vertical movable plunger 181 may be adapted for operation by a roller or the like as indicated for example on FIG. 1' of the aforesaid specification. In this case on each operation of the machine the roller 135 is depressed thereby actuating the plunger 131. The latter is connected at its upper end to a bell crank 132 the free arm of which is operatively coupled to a reciprocating slide 183 mounted on pins 184 by slots 185 in the slide. A return spring 186 tends to actuate the slide 133 on depression of the roller 135. 7

Spring actuated pawls 187 are provided on the slide 183 the working faces of said pawls engaging teeth of ratchet wheels 18 8 on the spool spindles 180.

Control of the pawls 187 so that one of them only is operative at a time is obtained by means of a spool changeover slide 189 lying to the rear of the slide 183 and supported on the same pins 184. Said slide is provided with angular forwardly directed projections 199 adapted in the two positions of the slide 139 to lift one or other of the pawls 187 out of engagement with the respective ratchet wheel 188. The upper edge of the slide 189 is provided with notches 193 engagable by the pointed tip 192 of a vertically movable slide 191 subjected to the action of a spring 194-, these components serving to locate the slide 189 in its two operative positions.

Each spool spindle 180 carries a pivoted member 195 which is pressed inwardly of the spool spindle as long as a certain amount of ribbon still remains on the spindle. The member 195 has an angular toe portion 1% which moves downwardly as a result of the pivotal motion of the member 195 when the ribbon is exhausted on that particular spool. As a result of the depression of the toe 196 it comes into the path of the projection 19% of the changeover slide 189 so that it strikes against the end face of one of the projections 19% and as it continues to rotate the slide 189 is displaced to its alternative position. Thereupon the pawl 187 actuating the ratchet Wheel 188 of the now exhausted spool is made operative and the other pawl 187 becomes inoperative so that the ribbon is reversed and winds on to the formerly exhausted spool. The path of the ribbon from one spool to the other comprises guide rollers 13? and it may if desired be guided towards the printing position by means of a suitable guide plate 1% adjacent the printing position.

The invention is not limited to the useof printing mechanism incorporating the aforesaid ribbon shift mechanism as it is also possible to employ an endless length of ribbon wherein a spare length may be stored concertina-wise in a suitable casing. Ribbon feeder rollers are in such case arranged at the point at which the ribbon enters the casing and braking rollers are provided at the exit point so that the portion of the ribbon outside the casing and exending in a path bringing it below the printing wheel is held under tension. Further a liquid medium to be applied to the ribbon may be contained in such casing and in the case, since a comparatively short length of tape will suffice, there is no need for a spare length to be stored in concertina fashion. The ribbon is only long enough to follow the desired path towards and away from the printing Wheels and to becarried beneath a guide roller in the casing which causes the ribbon to travel down into the liquid medium and upwardly.

label by the action of the ribbon 173. On completion of the printing operation the plunger 181 is actuated to shift the slide 183 to bring a new section of ribbon into the printing position. After one or more articles have been marked and it is desired to bring the next serial number into use the shift lever 162. is depressed and thus the numerals are stepped forward by one whereafter the next serial number is ready to be printed. Manual setting of the numerals is obtained when required by means of the index wheels 158 and in the embodiment described the latter characters can only be varied by adjustment of the corresponding index wheels. The marking for which the printing unit is set at any particular moment can always be seen by inspecting the markings on the index wheels 158.

It will be seen that an important feature is that the working face 175 of the pawl 169 normally remains clear of the operative faces of the printing wheels 110 and thus any possible damage to the printing faces is avoided; further this construction permits the printing characters forming a complete numeral to be placed very close one to the other while permitting a strong and rugged construction not liable to wear or accidential derangement. After the feed pawl 169 has actuated one or more of the printing wheels 110, the pawl 169 moves out of engagement with the printing wheel as a result of the action of the spring 174 on release of the shift lever 162 after which the return movement of the plate 166 carrying the pawl 169 commences. If desired, the pawl 169 may be positively controlled on its return movement so that it is forced to move out of engagement with the printing wheels 110 during this returns movement. This result may be obtained by providing a projecting pin on the pawl guided in a suitable track providing different paths for the downward feed movement and the upward idle movement, control of the pin to enter the return track being effected for example by means of a pivoted switch blade which closes the entry to the track followed on the downward movement. Alternatively the pawl 169 could be controlled by meals of a pivotal cam which is deflected from a stop by a pin on the pawl during this downward movement while on its return movement said pin catches against the cam which is thus pressed against the stop, and a curved face portion lifts the pawl clear of the number wheels during the said return movement.

What I claim is:

1. Mechanism for printing labels, comprising a set of printing wheels rotatable about a common axis and positioned in closely adjacent relation with substantially no space therebetween, each of said wheels having provided on its periphery alternately arranged printing characters and feed teeth, a movable carrier positioned to one side of said set of wheels and mounted for movement about said common axis, said carnier extending outwardly from such common axis to provide a portion thereof positioned beyond the peripheries of said printing wheels, a feed pawl mounted for pivotal movement on said carrier portion about an axis parallel to said common axis so as to be movable toward and away from said wheel peripheries, said feed pawl having an operable wheel-engaging end substantially equal in width to the overall width of said set of wheels and being of stepped formation to cooperate with the feed teeth on the peripheries of said wheels, the steps in smd pawl being joined in uninterrupted side-by-side relation and overlying the peripheries of their associated printing wheels, and an actuating lever connected to said feed pawl and operable on actuation thereof to cause a printing operation to initially pivot said pawl about its axis to move the operable end of said pawl toward the peripheries of sad wheels and into driving engagement with the feed teeth thereon, and then to impart translatory movement to said pawl by rotating the latter and sm'd carrier as a unit about said common axis and thereby apply a feed motion to the peripheries of said printing wheels, and means between said feed pawl and said carrier and being operable on the initial return movement of said actuating lever from such printing operation to pivot said feed pawl about its axis to withdraw the operable end of such pawl from engagement with said feed teeth and to bring such end to a position where it will be clear of the printing characters on said wheels during translatory movement of said said pawl back to its starting position as said actuating lever continues its return movement, and means for causing translatory movement of said pawl and rotational mo ement of said carrier plate back to their starting positions.

2. Mechanism such as defined in claim 1, in which said feed pawl is fixed to one end of said actuating lever so that said pawl and said lever pivot as a unit about said pawl axis.

3. Mechanism such as defined in claim 1, in which said movable carrier portion has an oscillatable movement about said common axis in the operation of the mechanism, and in which said means between said pawl and said carrier includes spring means for normally biasing said carrier to move said portion to a starting position, and a stop coact-ing with said carrier to fix the starting position of sau'd portion.

4. Mechanism such as defined in claim 1, in which said means between said pawl and said carrier includes spring means mounted on said carrier and tending to normmly maintain said pawl in a withdrawn position relative to said printing wheels.

5. Mechanism for printing labels, comprising a plurality of independently rotatable coaxial printing wheels in facial contact and each having on the peripheral face thereof printing characters alternating with feed teeth, a displaceable carrier plate adjacent said plurality of printing wheels and rotatable independently of said printing wheels and coaximly therewith, said plate having a portion thereof located externally of the peripheral faces of the printing wheels, wheel-engaging means pivotally mounted on said portion of said carrier plate so as to be movable toward and away from the peripheral faces of the printing wheels and spanning a plurality of said printing wheels, an actuating lever rigidly connected to said wheel-engaging means to form a unit pivoted to the carrier plate to cause said means to move radially inwardly towards the axis of the printing Wheels to engage said feed teeth on the peripheral faces of the wheels, 2. spring between said carrier plate and said unit and operable to enable said wheel-engaging means to be brought into driving engagement with the wheels on initial operation of the actuating lever in the feed direction to drive said wheels and then toenable said actuating lever to operate said wheel-engaging means and said carrier plate to advance the characters serially in continued movement of said lever in said direction, and to cause said wheel-engaging means to become disengaged from the wheels on the return movement of said actuating lever and thus enable said wheel-engaging means to move clear of the printing characters on said wheel during an idle return movement of said actuating lever and a second spring connected to said carrier plate for biasing the return of said carrier plate to the starting position.

References Cited in the file of this patent UNITED STATES PATENTS 96,990 Soule NOV. 16, 1869 254,827 Kidder Mar. 14, 1882 293,199 Seybold Feb. 5, 1884 953,819 Conrad Apr. 5, 1910 1,032,769 Post July 16, 1912 1,324,469 Scott Dec. 9, 1919 1,554,283 Kern Sept. 22, 1925 1,695,964 Lang Dec. 18, 1928 2,364,345 Cooper Dec. 5, 1944 2,528,740 Carothers et al. Nov. 7, 1950 

1. MECHANISM FOR PRINTING LABELS, COMPRISING A SET OF PRINTING WHEELS ROTATABLE ABOUT A COMMON AXIS AND POSITIONED IN CLOSELY ADJACENT RELATION WITH SUBSTANTIALLY NO SPACE THEREBETWEEN, EACH OF SAID WHEELS HAVING PROVIDED ON ITS PERIPHERY ALTERNATELY ARRANGED PRINTING CHARACTERS AND FEED TEETH, A MOVABLE CARRIER POSITIONED TO ONE SIDE OF SAID SET OF WHEELS AND MOUNTED FOR MOVEMENT ABOUT SAID COMMON AXIS, SAID CARRIER EXTENDING OUTWARDLY FROM SUCH COMMON AXIS TO PROVIDE A PORTION THEREOF POSITIONED BEYOND THE PERIPHERIES OF SAID PRINTING WHEELS, A FEED PAWL MOUNTED FOR PIVOTAL MOVEMENT ON SAID CARRIER PORTION ABOUT AN AXIS PARALLEL TO SAID COMMON AXIS SO AS TO BE MOVABLE TOWARD AND AWAY FROM SAID WHEEL PERIPHERIES, SAID FEED PAWL HAVING AN OPERABLE WHEEL-ENGAGING END SUBSTANTIALLY EQUAL IN WIDTH TO THE OVERALL WIDTH OF SAID SET OF WHEELS AND BEING OF STEPPED FORMATION TO COOPERATE WITH THE FEED TEETH ON THE PERIPHERIES OF SAID WHEELS, THE STEPS IN SAID PAWL BEING JOINED IN UNINTERRUPTED SIDE-BY-SIDE RELATION AND OVERLYING THE PERIPHERIES OF THEIR ASSOCIATED PRINTING WHEELS, AND AN ACTUATING LEVER CONNECTED TO SAID FEED PAWL AND OPERABLE ON ACTUATION THEREOF TO CAUSE A PRINTING OPERATION TO INITIALLY PIVOT SAID PAWL ABOUT ITS AXIS TO MOVE THE OPERABLE END OF SAID PAWL TOWARD THE PERIPHERIES OF SAID WHEELS AND INTO DRIVING ENGAGEMENT WITH THE FEED TEETH THEREON, AND THEN TO IMPART TRANSLATORY MOVEMENT TO SAID PAWL BY ROTATING THE LATTER AND SAID CARRIER AS A UNIT ABOUT SAID COMMON AXIS AND THEREBY APPLY A FEED MOTION TO THE PERIPHERIES OF SAID PRINTING WHEELS, AND MEANS BETWEEN SAID FEED PAWL AND SAID CARRIER AND BEING OPERABLE ON THE INITIAL RETURN MOVEMENT OF SAID ACTUATING LEVER FROM SUCH PRINTING OPERATION TO PIVOT SAID FEED PAWL ABOUT ITS AXIS TO WITHDRAW THE OPERABLE END OF SUCH PAWL FROM ENGAGEMENT WITH SAID FEED TEETH AND TO BRING SUCH END TO A POSITION WHERE IT WILL BE CLEAR OF THE PRINTING CHARACTERS ON SAID WHEELS DURING TRANSLATORY MOVEMENT OF SAID SAID PAWL BACK TO ITS STARTING POSITION AS SAID ACTUATING LEVER CONTINUES ITS RETURN MOVEMENT, AND MEANS FOR CAUSING TRANSLATORY MOVEMENT OF SAID PAWL AND ROTATIONAL MOVEMENT OF SAID CARRIER PLATE BACK TO THEIR STARTING POSITIONS. 